Make Disciples ANSWERING THE WHY, WHAT, AND HOW OF OUR MISSION.
Answering the Question: Why? Factors Affecting Change in Water Quality Exceptional challenge to...
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Answering the Question: Why? Factors Affecting Change in Water Quality • Exceptional challenge to explain “why” • Poor quality of pollution source information • Ex. Ag source sector has poor information on BMP implementation (due in part to Farm Bill privacy issues and technical limitations of NRCS.) • Many assumptions (with errors associated with them) are required to generate a time series of source information • Lag time issue of pollutants in surface and ground water • Expectation for change is not realistic given degree of management practice implementation • Explaining change is hard in large rivers given multiple pollutants however, explaining change in the point sources is possible • Ex. Point source controls are the explanation for most decreases in nutrients in large CBW rivers since 1980s • Smaller systems allow for understanding of factors affecting change • Monitoring is moving to from large river focus to monitoring some small watersheds where large amounts of practice implementation is planned or ongoing in order to better describe factors affection change. • Point source easier to explain than non point source
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Transcript of Answering the Question: Why? Factors Affecting Change in Water Quality Exceptional challenge to...
Answering the Question: Why?Factors Affecting Change in Water Quality• Exceptional challenge to explain “why”
• Poor quality of pollution source information• Ex. Ag source sector has poor information on BMP implementation (due
in part to Farm Bill privacy issues and technical limitations of NRCS.) • Many assumptions (with errors associated with them) are required to
generate a time series of source information• Lag time issue of pollutants in surface and ground water • Expectation for change is not realistic given degree of management practice
implementation• Explaining change is hard in large rivers given multiple pollutants however,
explaining change in the point sources is possible• Ex. Point source controls are the explanation for most decreases in
nutrients in large CBW rivers since 1980s• Smaller systems allow for understanding of factors affecting change
• Monitoring is moving to from large river focus to monitoring some small watersheds where large amounts of practice implementation is planned or ongoing in order to better describe factors affection change.
• Point source easier to explain than non point source
Flow-Adjusted Concentration Trends
1985-2008:Total Phosphorus
22 downward trends
4 upward trends
8 non-significant trends
Flow-Adjusted Concentration Trends
1985-2008:Total Nitrogen
25 downward trends
2 upward trends
7 non-significant trends
Flow-Adjusted Concentration Trends 1985-2008:Total Sediment13 downward trends
2 upward trends
19 non-significant trends
Wastewater Discharge Locations: Patuxent River WatershedData Source:
Chesapeake Bay Program:
Point Source Database
20 Locations upstream from USGS Patuxent River Gage
Significant Investment(s) in treatment technology
Phosphorus Detergent Ban
Watershed Changes:
Urban/Suburban devt.
Land Conversion
Population increase
NPS management
SWM management
Large Point-Source Reductions Yield Measurable Improvements in Phosphorus Concentrations
Annual Point source Discharges Upstream from Patuxent River Monitoring Station
Observed Concentrations atPatuxent River Monitoring Station
44 years of Nitrate concentration data show long-term increases in an agricultural setting:Choptank River at Greensboro, MD
Groundwater Models Develop Nutrient Loading Forecasts
Eastern Shore of Virginia
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